1. Field of the Invention
This invention relates to an aircraft undercarriage including a downlock mechanism.
2. Discussion of Prior Art
An aircraft undercarriage normally includes a downlock mechanism which ensures that the deployed undercarriage forms a stable structure, which does not collapse under normal operational ground loading. This is normally done by providing a drag stay extending in a straight line such that loads are transferred efficiently into the aircraft structure. Particularly where the landing gear is a main body landing gear with braked wheels, the stay and support structure need to be capable of withstanding considerable loads. In addition the aircraft undercarriage is required to retract into a compact space within the undercarriage bay, which is usually determined by factors such as the spacing between adjacent structural bulkheads and so stringent demands are placed on the designer to provide an undercarriage capable of being stowed within the allocated space whilst being capable of reliably reacting the usual loads when deployed.
Further complications are introduced when the undercarriage has a four or more wheeled bogey because the bogey itself occupies a large amount of space and also the landing gear and downlock mechanism must be capable of moving between the retracted and deployed positions without the bogey or wheels colliding with the undercarriage mechanism. A yet further problem in designing such arrangements is the need to ensure that potentially secure locking arrangements are not prejudiced by relative movement or flexing of the undercarriage relative to the aircraft structure.